Dark Energy and Projective Symmetry
arXiv:1003.3845 · doi:10.1016/j.physletb.2010.04.016
Abstract
Nurowski [arXiv:1003.1503] has recently suggested a link between the observation of Dark Energy in cosmology and the projective equivalence of certain Friedman-Lemaitre-Robertson-Walker (FLRW) metrics. Specifically, he points out that two FLRW metrics with the same unparameterized geodesics have their energy densities differing by a constant. From this he queries whether the existence of dark energy is meaningful. We point out that physical observables in cosmology are not projectively invariant and we relate the projective symmetry uncovered by Nurowski to some previous work on projective equivalence in cosmology.
References in corpus (3)
Cited by in corpus (6)
- Photon Spheres and Sonic Horizons in Black Holes from Supergravity and Other Theories
- Geodesically equivalent metrics in general relativity
- Conformal and projective symmetries in Newtonian cosmology
- Dark Energy From Dynamical Projective Connections
- Optical Metrics and Projective Equivalence
- What is the meaning of non-uniqueness of FRW and Schwarzschild metrics?